Rotation plus vibration magnet for magnetron sputtering apparatus

ABSTRACT

In some embodiments, the present disclosure relates to a plasma processing system comprising a magnetron configured to provide a symmetric magnetic track through a combination of vibrational and rotational motion. The disclosed magnetron comprises a magnetic element configured to generate a magnetic field. The magnetic element is attached to an elastic element connected between the magnetic element and a rotational shaft configured to rotate magnetic element about a center of the sputtering target. The elastic element is configured to vary its length during rotation of the magnetic element to change the radial distance between the rotational shaft and the magnetic element. The resulting magnetic track enables concurrent motion of the magnetic element in both an angular direction and a radial direction. Such motion enables a symmetric magnetic track that provides good wafer uniformity and a short deposition time.

BACKGROUND

Integrated chips are formed by complex fabrication processes, duringwhich a workpiece is subjected to different steps to form one or moresemiconductor devices. Some of the processing steps may comprise forminga thin film onto a semiconductor substrate. Thin films can be depositedonto a semiconductor substrate in a low-pressure processing chamberusing physical vapor deposition.

Physical vapor deposition is typically performed by acting on a targetwith plasma comprising a plurality of high energy ions. The high energyions collide with the target, dislodging particles into a vapor. Thevapor is transported to a semiconductor substrate, upon which the vaporaccumulates to form a thin film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a illustrates a cross-sectional view of a physical vapordeposition system comprising a magnetron.

FIG. 1 b illustrates a top view of the magnetron shown in FIG. 1 a.

FIG. 1 c illustrates an exemplary magnetic track achieved by themagnetron shown in FIG. 1 b.

FIG. 2 illustrates a top view of some embodiments of a physical vapordeposition system comprising a magnetron configured to provide asymmetric magnetic track through a combination of vibrational androtational motion.

FIG. 3 illustrates a cross-sectional view of some embodiments of aphysical vapor deposition system comprising a magnetron configured toprovide a symmetric magnetic track through a combination of vibrationaland rotational motion.

FIG. 4 illustrates a top view of some more detailed embodiments of aphysical vapor deposition system comprising a magnetron configured toprovide a symmetric magnetic track achieved through vibration plusrotation.

FIG. 5 illustrates a three dimensional view of some embodiments of asecondary outside magnet configured to induce vibrational motion in themagnetron.

FIGS. 6 a-6 b show some exemplary top views of states of the disclosedmagnetron over time.

FIGS. 7 a-7 d illustrates some exemplary magnetic tracks that can beachieved by the disclosed magnetron.

FIGS. 8 a-8 b illustrate side views of some embodiments of an elasticelement comprising a pneumatic valve.

FIGS. 9 a-9 b illustrate side views of some embodiments of an elasticelement comprising a gear based design.

FIG. 10 illustrates a side view of some embodiments of an elasticelement comprising a screw based design.

FIG. 11 illustrates a flow diagram of some embodiments of a method foroperating a magnetron configured to provide a symmetric magnetic trackachieved through vibration plus rotation.

DETAILED DESCRIPTION

The description herein is made with reference to the drawings, whereinlike reference numerals are generally utilized to refer to like elementsthroughout, and wherein the various structures are not necessarily drawnto scale. In the following description, for purposes of explanation,numerous specific details are set forth in order to facilitateunderstanding. It may be evident, however, to one of ordinary skill inthe art, that one or more aspects described herein may be practiced witha lesser degree of these specific details. In other instances, knownstructures and devices are shown in block diagram form to facilitateunderstanding.

FIG. 1 a illustrates a cross-sectional view of a physical vapordeposition system 100. The physical vapor deposition system 100comprises a processing chamber 102 having a support pedestal 106configured to hold a workpiece 104. A coil 108, connected to a powergenerator 110 operating at an RF frequency (e.g., 13.56 MHz), isconfigured to generate a magnetic field that transfers energy from thepower generator 110 to gas particles within the processing chamber 102to form a plasma 112. A target 114, located at the top of the processingchamber 102, is coupled to a high voltage D.C. power source 116configured to apply a bias to the target 114. The bias causes highenergy ions from the plasma 112 to sputter the target 114 and generatetarget atoms 118. The target atoms 118, after being ionized by coil 108are attracted to the workpiece 104 (upon which they condense to form athin film) by the magnetic field generated by the coil 108 and by a biasapplied to the workpiece 104 by a power generator 120 coupled to thesupport pedestal 106.

A magnetron 122 is positioned on the back side of the target 114. Themagnetron 122 comprises a magnetic element 124 that is rotated by amotor 128. The magnetic element 124 may be submerged in water (providedvia inlet 129 a and outlet 129 b) for cooling purposes. Duringsputtering, the magnetic element 124 is configured to generate amagnetic field 126. The magnetic field 126 acts with a force on ionswithin the plasma 112 to trap the ions close to the target 114. Thetrapped ions collide with neutral gas particles near the target 114,enhancing ionization of the plasma 112 near the target 114 and leadingto a higher sputter rate.

As illustrated in a top view 130 of the magnetron, shown in FIG. 1 b,the magnetic element 124 and a first counter weight 132 are configuredto rotate around a first pivot point 134, which is attached to a rigidstructure 136 configured to rotate about a second pivot point 138. Asillustrated in a top view 140, shown in FIG. 1 c, such a magnetrondesign provides for a magnetic track 142 that progresses around thetarget 114 over more rotational cycles (i.e., a large number ofrotational cycles). The more rotational cycles, combined with arelatively slow movement of the magnetic element when submerged in waterfor cooling, means that a relatively large time is needed for themagnetic element 124 to achieve complete coverage of the target 114 andto get a good wafer uniformity due to the more rotation cycles.

Accordingly, the present disclosure relates to a plasma processingsystem comprising a magnetron configured to provide an adjustable,symmetric magnetic track through a combination of vibrational androtational motion. In some embodiments, the disclosed magnetroncomprises a magnetic element configured to generate a magnetic field.The magnetic element is attached to an elastic element connected betweenthe magnetic element and a rotational shaft configured to rotate themagnetic element about a center of the sputtering target. The elasticelement is configured to vary its length during rotation of the magneticelement to change the radial distance between the rotational shaft andthe magnetic element to enable concurrent motion of the magnetic elementin both an angular direction and a radial direction. Such motion allowsfor an adjustable, symmetric magnetic track that provides good waferuniformity in a short deposition time.

FIG. 2 illustrates a top view of some embodiments of a physical vapordeposition system 200 comprising a magnetron configured to provide anadjustable, symmetric magnetic track achieved through a combination ofvibrational and rotational motion.

The magnetron comprises a magnetic element 202 configured to generate amagnetic field within a processing chamber 216 configured to house aworkpiece (not shown). The magnetron further comprises a firstambulatory element configured to move the magnetic element 202 in anangular (i.e., rotational) direction and a second ambulatory elementconfigured to linearly move the magnetic element 202 in a radialdirection concurrent to the angular motion. The concurrent angular andradial motion of the magnetic element 202 enables the magnetic element202 to move along a symmetric magnetic track 210. The symmetric magnetictrack 210 provides for good target utilization (i.e., full face erosionof target) while ensuring good deposition uniformity in a short time.

In some embodiments, the first ambulatory element comprises a rotationalshaft 204 and the second ambulatory element comprises an elastic element206 having a variable length. The magnetic element 202 is connected tothe elastic element 206. The elastic element 206 extends from themagnetic element 202 to the rotational shaft 204, which is located atapproximately the center of a sputtering target 114. The elastic element206 is configured to vary its length, varying the distance of themagnetic element 202 with respect to the center of the target 114. Therotational shaft 204 is configured to concurrently rotate the magneticelement 202 about the center of the sputtering target 114 allowing themagnetic element 202 to follow the symmetric magnetic track 210. In someembodiments, the rotational shaft 204 is connected to a motor configuredto turn the rotational shaft 204. By changing the speed of rotationand/or the speed and/or magnitude of changes in length, a symmetricmagnetic track 210 having an adjustable path can be achieved.

In some embodiments, a secondary outside magnet 212 is located aroundthe perimeter of the sputtering target 114. The secondary outside magnet212 may comprise a plurality of permanent magnets or electromagnetspositioned around the perimeter of the sputtering target 114. Thesecondary outside magnet 212 is configured to generate a secondarymagnetic field that operates upon the magnetic element 202 with arepulsive force. The repulsive force 214 pushes the magnetic element 202radially inward causing a change in the radial position of the magneticelement 202 (i.e., causing the length of the elastic element 206 tochange). The repulsive force 214 opposes a centrifugal force, generatedby rotation of the magnetic element, which pushes the magnetic element202 outward. Together, the centrifugal force and the repulsive forcegenerate a radially vibrational motion (i.e., a vibration motion in aradial direction) illustrated by the magnetic track 210.

In some embodiments, a counter weight 208 is located at a position alongthe elastic element 206 that opposes the position of the magneticelement 202. For example, as shown in FIG. 2, counter weight 208 andmagnetic element 202 are on opposite sides of the rotational shaft 204.The counter weight 208 is configured to stabilize the magnetic element202 by balancing the load of the magnetic element 202. This compensatesfor the weight of the magnetic element 202 and maintains balance in arotational plane of the magnetron.

FIG. 3 illustrates a side view of some embodiments of a physical vapordeposition system 300 comprising a magnetron configured to provide anadjustable, symmetric magnetic track through a combination ofvibrational and rotational motion.

As shown in FIG. 3, the rotational shaft 204 is located along an axis ofrotation 302 that extends through the center of the sputtering target114. The magnetron is located on a backside of sputtering target 114(i.e., an opposite side of the target 114 as a workpiece 104), such thatmagnetic element 202 is configured to generate one or more magneticfields 304 that extend through the sputtering target 114 to a regionbelow the sputtering target 114. The magnetic fields 304 operate uponions within a processing chamber to enhance the ionization of plasmanear the sputtering target 114, leading to a higher sputter rate.

The magnetic element 202 may comprise any type or number of magnets. Insome embodiments, the magnetic element 202 comprises one or morepermanent magnets (e.g., neodymium magnets). Furthermore, the magneticelement 202 may comprise any size of magnets. As shown in FIG. 3, insome embodiments, the magnetic element 202 comprises a plurality ofsmall magnets 202 a-202 d.

By placing small magnets having opposite polarities next to one another,one or more magnetic fields 304 having a high density can be achievedbelow the sputtering target 114. The high density of the magnetic fields304 provides for good step coverage and good deposition symmetry overthe surface of a workpiece 104. For example, thin film 306 is depositedto have symmetry between the deposited films on opposing sidewalls of atrench and to have a film thickness on the trench sidewalls that isapproximately equal to the film thickness at the bottom of the trench.

The secondary outside magnet 212 is configured to have a magneticpolarity that generates a repulsive force 214 on the magnetic element202. For example, magnetic elements 202 d and 212 a are configured tohave a same magnetic configuration (e.g., a south magnetic pole locatedabove a north magnetic pole). The configurations cause the like poles toact upon each other with a repulsive force 214 that opposes an outwardcentrifugal force to push the magnetic element 202 inward.

FIG. 4 illustrates a top view of some alternative embodiments of amagnetron 400 disclosed herein.

The magnetron 400 comprises a magnetic element 202 comprising concentricring shaped magnets. In some embodiments, the concentric ring shapedmagnets comprise an inner ring-shaped magnet 402 and an outerring-shaped magnet 404, wherein the diameter of the inner ring-shapedmagnet 402 is smaller than a diameter of the outer ring-shaped magnet404. The inner and outer ring-shaped magnets 402 and 404 have a samemagnetic polarity (e.g., a north magnetic pole facing outward and asouth magnetic pole facing inward). In some embodiments, the inner andouter ring shaped magnets 402 and 404 comprise a plurality of stripmagnets configured parallel to the ring's axis, such that adjacent stripmagnets have opposing magnetic pole orientations.

In some embodiments, the magnetron 400 comprises an electromagneticsecondary outside magnet 406. The electromagnetic secondary outsidemagnet 406 is configured to vary the strength of the secondary magneticfield it generates based upon a current value provided to theelectromagnetic secondary outside magnet 406. By changing the strengthof the secondary magnetic field generated by the electromagneticsecondary outside magnet 406, a magnitude of variation in the radiallength in the elastic element (i.e., an elastic length) can be changed.For example, by decreasing the secondary magnetic field strengthgenerated by the electromagnetic secondary outside magnet 406, theelastic length is decreased (i.e., the elastic element will vary itsradial position by a decreased amount).

In some embodiments, the electromagnetic secondary outside magnet 406 islocated outside of a grounded chamber shielding 408 configured toconfine plasma and protect the sidewalls of a processing chamber fromdeposition. In some embodiments, the secondary magnetic field generatedby the electromagnetic secondary outside magnet 406 can be chosen tohave a strength that prevents the magnetic element from hitting thechamber shielding 408.

In some embodiments, the elastic element 206 comprises a power system410 configured to control changes in length of the elastic element 206.For example, the power system 410 may comprise a motor configured tocontrol the length of the elastic element 206 and/or the speed at whichthe length of the elastic element 206 changes. By changing the length ofthe elastic element 206 the position of the magnetic element 202relative to the sputtering target 114 is changed. Furthermore, themagnitude of the elastic length is changed. This is because changing thedistance between the electromagnetic secondary outside magnet 406 andthe magnetic element 202 also changes the magnitude of the repulsiveforce. For example, by decreasing the length of the elastic element 206,the magnetic element 202 is moved further from the electromagneticsecondary outside magnet 406, reducing the strength of the repulsiveforce 214 and reducing changes in the elastic length of the elasticelement 206.

FIG. 5 illustrates some embodiments of a physical vapor depositionsystem 500 having a secondary outside magnet 502 comprising a pluralityof electromagnetic coils 502 a, 502 b. The electromagnetic coils 502 a,502 b can be operated to adjust the repulsive force between the magneticelement 202 and the secondary outside magnet 502.

The electromagnetic coils 502 a, 502 b comprise a winding ofelectrically conducting wire 504. When current is passed through theelectrically conducting wire 504, it generates a magnetic fieldproportional to the current (i.e., B=μ₀ni, where B is the magneticfield, μ₀ is the is the permeability of free space (4·π·10⁻⁷ V·s/(A·m)),n is the number of turns of the wire, and i is the current passedthrough the wire). Therefore, the strength of the magnetic fieldgenerated by the secondary outside magnet 500 can be dynamically variedby changing the current provided to the conductive wire 504.

In some embodiments, the electromagnetic coils 502 a, 502 b are orientedsuch that the axes 506 extending through the center of electromagneticcoils 502 a and 502 b intersect the rotational shaft 204 of themagnetron. Since the electromagnetic coils 502 a, 502 b are composed ofconducting wire 504 that wraps around the axes 506, current flowsthrough the electromagnetic coils 502 a, 502 b in a direction thatgenerates magnetic fields along the axes 506 (i.e., which isperpendicular to the perimeter of sputtering target 114). By controllingthe direction of current through the electromagnetic coils 502, theelectromagnetic coils 502 a, 502 b can be operated to change theorientation of the generated magnetic field. For example, when currentis provided to electromagnetic coils 502 a, 502 b in a first direction amagnetic field having a first magnetic orientation will result.Alternatively, when current is provided to electromagnetic coils 502 a,502 b in a second direction opposite the first direction, a magneticfield having a second magnetic orientation opposite the firstorientation will result.

As shown in FIG. 5, the direction of the current flow is chosen togenerate a magnetic field that is radially inward causingelectromagnetic coils 502 a, 502 b to have a north pole (N) located atthe inward edge of the coil and a south pole (S) located at the outeredge of the coil. Alternatively, if the direction of the current flow ischosen to generate a magnetic field that is radially outward, theelectromagnetic coils 502 a, 502 b will have a north pole (N) located atthe outer edge of the coil and a south pole (S) located at the inneredge of the coil.

FIGS. 6 a-6 b show some exemplary top views of states of a disclosedmagnetron during different times of operation.

FIG. 6 a illustrates a first state 600 of a magnetron at a first timet₁. The magnetic element 202 of the magnetron is located at an angle ofθ₁ and at a distance of d₁ from the center of the sputtering target 114.

FIG. 6 b illustrates a second state 602 of the magnetron at a secondtime t₂, which is later than the first time t₁. From the first time t₁to the second time t₂, the magnetic element 202 has progressed by anangle of Δθ, causing the magnetic element 202 of the magnetron to belocated at an angle of θ₂>θ₁. The magnetic element 202 has alsodecreased its distance from the center of the sputtering target 114 to adistance d₂<d₁. Therefore, over time the magnetic element 202 hasundergone both a change in angular position (e.g., from θ₁ to θ₂) and achange in radial position (e.g., from d₁ to d₂).

By varying the rotational frequency, the variable length of the elasticelement, and/or the elastic length of the elastic element, the path ofthe magnetic track can be changed. For example, FIGS. 7 a-7 d illustratemagnetic tracks (i.e., paths that magnetic element 202 follows) obtainedthrough various combinations of rotational frequency, changes in thelength of the elastic element, and changes in the elastic length. Itwill be appreciated that the magnetic tracks are examples of thesymmetric magnetic tracks that can be achieved by the disclosedmagnetron and are not limiting to motion of the magnetron disclosedherein. Furthermore, it will be appreciated that the length of theelastic element is illustrated as a unitless quantity between 0-10units. The value of the unitless quantity will vary depending on a sizeof the target used. For example, for a target having a diameter of 100mm, a unitless quantity is half of that of a unitless quantity for atarget having a diameter of 200 mm (e.g., a unit for a 100 mm target is10 mm, a unit for a 200 mm target is 20 mm).

FIG. 7 a illustrates a top view 700 of an embodiment of an exemplarymagnetic track 702. Magnetic track 702 has an elastic length of 6 units.This means that the magnetic element is able to change its radialposition by six units, for example from a distance of 4 units to adistance of 10 units from the center of the target (i.e., from 0 units).The magnetic track 702 also has an elastic period equal to ⅙^(th) of arotational period. This means that during one rotation the magnetictrack 702 will expand and then return to a specific radial value sixtimes.

FIG. 7 b illustrates a top view 704 of an embodiment of a first modifiedmagnetic track 706. The first modified magnetic track 706 illustrateschanges to magnetic track 702 that can be achieved by increasing therotational frequency of the magnetic element. In some embodiments, therotational frequency can be increased by increasing the rotational speedof the magnetic element. By increasing the rotational speed of themagnetic element, the magnetic element expands and returns to itsoriginal radial value less times during a rotation. For example, thefirst modified magnetic track 706 has an elastic period equal to ⅓^(rd)of a rotational period, such that during one rotation the magnetic trackwill expand and then return to its original radial value three times.

FIG. 7 c illustrates a top view 708 of an embodiment of second modifiedmagnetic track 710. The second modified magnetic track 710 illustrateschanges to magnetic track 702 achieved by decreasing the elastic lengthof the elastic element. In some embodiments, the elastic length can bedecreased by changing the secondary magnetic field strength (andtherefore the repulsive force) generated by the secondary outsidemagnet. By decreasing the secondary magnetic field strength generated bythe secondary outside magnet, the magnetic element changes its radialposition by a smaller amount. For example, the second modified magnetictrack 710, having an elastic length of 4 units, is configured to changeits radial position from a distance of 6 units to a distance of 10 unitsfrom the center of the target (e.g., to elastically vary from 8 to 10and from 8 to 6).

FIG. 7 d illustrates a top view 712 of an embodiment of a third modifiedmagnetic track 714. The third modified magnetic track 714 illustrateschanges to magnetic track 702 achieved by decreasing the variable lengthof the elastic element. By decreasing the variable length of the elasticelement, the magnetic element changes its position around a positionthat is closer to the target center. For example, the third modifiedmagnetic track 714 is configured to change its radial position around adistance of 5 units from the center of the target. Furthermore,decreasing the length of the elastic element moves the magnetic elementfurther from the secondary magnetic element, reducing the strength ofthe repulsive force and the elastic length of the elastic element. Forexample, the third modified magnetic track 714 has an elastic length of2 units.

It will be appreciated that the elastic element disclosed herein maycomprise a variety of extendable structures. FIGS. 8 a-10 illustratethree possible embodiments of an elastic element configured to vary theradial position of a disclosed magnetron's magnetic element.

FIGS. 8 a-8 b illustrate block diagrams of some embodiments of amagnetron 800 comprising an elastic element 802 having a pneumatic valve804.

The magnetron 800 comprises a motor 128 configured to rotate arotational shaft 204 around an axis of rotation 302 that extends throughthe center of a sputtering target 114. The rotational shaft 204 isconnected to a cantilevered structure of the magnetron comprising acylinder 806, an elastic element 802, and the magnetic element 202. Itwill be appreciated that the elastic element 802 may comprise thecylinder 806 along with one or more elastic components connected betweenthe rotational shaft 204 and the magnetic element 202. The one or moreelastic components provide for an elasticity that allows for themagnetic element 202 to move in a radially vibrational motion.

The pneumatic valve 804 is configured to control the flow of air,allowing for air to enter and leave the cylinder 806, which has amoveable piston 810. The piston 810 is connected to a spring 808 on oneside and the magnetic element 202 on the other side. As air enters thecylinder 806 through the pneumatic valve 804, the pressure of the airpushes on the piston 810 expanding the spring 808 from its equilibriumposition.

As shown in FIG. 8 a, when the pneumatic valve 804 is closed, air cannotescape from the cylinder 806 and the magnetic element 202 is at a firstmedian distance d₁ from axis of rotation 302 (i.e., a distance d₁ aroundwhich the elastic element can vibrate). As shown in FIG. 8 b, when thepneumatic valve 804 is open, compressed air is driven out of thecylinder 806 by the force exerted by the spring 808 as it returns to itsequilibrium position. As the spring 808 contracts, the piston 810 moves,changing the position of the magnetic element 202 to a second mediandistance d₂ from axis of rotation 302. Therefore, by opening and closingthe pneumatic valve 804, the elastic element 802 can change the positionof a magnetic element 202 relative to the axis of rotation 302.

FIGS. 9 a-9 b illustrates block diagrams of some embodiments of amagnetron 900 comprising an elastic element 908 having a lead screwdesign.

The magnetron 900 comprises a first motor 128 configured to rotate arotational shaft 204 around an axis of rotation 302 that extends throughthe center of a sputtering target 114. The rotational shaft 204 isconnected to a gear box 902 containing a second motor 904. The gear box902 is connected to a screw shaft 906. A first end of the screw shaft906 is connected to magnetic element 202 (e.g., by way of one or moreelastic components) and a second end of the screw shaft 906 is connectedto a counter weight 208.

The gear box 902 is configured to turn a screw shaft 906, therebytranslating a turning motion of the second motor 904 into a linearmotion that changes the position of magnetic element 202 relative to thegear box 902. In some embodiments, the first and second ends of thescrew shaft have opposite threading directions, so that as the screwshaft 906 turns, the opposite threading directions move the magneticelement 202 and the counter weight 208 in opposite directions.

For example, as shown in FIG. 9 a, magnetic element 202 is located at afirst median distance d₁ from axis of rotation 302. By turning the screwshaft 906, magnetic element 202 is moved to a second median distance d₂from axis of rotation 302, as shown in FIG. 9 b. Furthermore, due to theopposing thread directions, the counter weight 208 is moved in anopposite direction. In some embodiments, the magnetic element 202 andcounter weight 208 are configured to move in opposite directions at thesame velocity. However, it will be appreciated that the relative motionsof the counter weight 208 and magnetic element 202 can be adjusted basedupon threading characteristics.

FIG. 10 illustrates a block diagram of some embodiments of a magnetron1000 comprising an elastic element 1010 having a worm drive gear design.

The magnetron 1000 comprises a first motor 128 configured to rotate arotational shaft 204 around an axis of rotation 302 that extends throughthe center of a sputtering target 114. The rotational shaft 204 isconnected to a gear box 1002 containing a second motor 1004. The secondmotor 1004 is configured to drive a worm wheel 1006, having teeth withedges that are straight and aligned parallel to the axis of rotation,meshed with a worm gear 1008 (i.e., in the form of a screw).

A magnetic element 202 is connected to one end of the worm gear 1008(e.g., by way of one or more elastic components) while a counter weight208 is connected on an opposite end of the worm gear 1008. As the secondmotor 1004 turns the worm wheel 1006, the worm gear 1008 moves themagnetic element 202 and the counter weight 208 in a same direction,changing the location of the magnetic element 202 with respect to axisof rotation 302.

FIG. 11 illustrates a flow diagram of some embodiments of a method 1100for operating a magnetron configured to provide an adjustable, symmetricmagnetic track achieved through a combination of vibrational androtational motion. While method 1100 is illustrated and described belowas a series of acts or events, it will be appreciated that theillustrated ordering of such acts or events are not to be interpreted ina limiting sense. For example, some acts may occur in different ordersand/or concurrently with other acts or events apart from thoseillustrated and/or described herein. In addition, not all illustratedacts may be required to implement one or more aspects or embodiments ofthe description herein. Further, one or more of the acts depicted hereinmay be carried out in one or more separate acts and/or phases.

At step 1102 a bias is applied to a sputtering target within aprocessing chamber. The bias causes high energy ions from a plasmawithin the processing chamber to sputter the sputtering target andgenerate target atoms.

At step 1104 a power source is operated to provide power to a magnetroncomprising a magnetic element positioned on backside of sputteringtarget to generate one or more magnetic fields that extend through thesputtering target.

At step 1106 a first ambulatory element is operated to concurrently movethe magnetic element in an angular direction. The angular directionextends tangentially to the radial direction. In some embodiments, thefirst ambulatory element comprises a rotational shaft connected to theelastic element and configured to rotate the elastic element around arotational axis.

At step 1108 a second ambulatory element is operated to linearly movemagnetic element in a radial direction. The radial direction extendsradially outward from a center of the sputtering target. In someembodiments, the second ambulatory element comprises an elastic elementconfigured to change its length. The elastic element may comprise apneumatic valve spring, a lead screw, or a worm drive. In someembodiments, the second ambulatory element further comprises a secondaryoutside magnet operated to generate a repulsive force in a radiallyinward direction. The repulsive force is opposed by an outwardcentrifugal force to achieve a vibrational motion in the radialdirection.

Together, the first and second ambulatory elements enable concurrentmotion of the magnetic element in both an angular direction and a radialdirection to enable symmetric magnetic vibration plus rotation track.The symmetric magnetic track ensures good wafer uniformity in a smalldeposition time.

At step 1110 one or more operating parameters of the magnetron areadjusted to vary the magnetic track, in some embodiments. In variousembodiments, the one or more operating parameters may comprise therotational frequency, the variable length of the elastic element, and/orthe elastic length of the elastic element.

It will also be appreciated that equivalent alterations and/ormodifications may occur to one of ordinary skill in the art based upon areading and/or understanding of the specification and annexed drawings.The disclosure herein includes all such modifications and alterationsand is generally not intended to be limited thereby. In addition, whilea particular feature or aspect may have been disclosed with respect toonly one of several implementations, such feature or aspect may becombined with one or more other features and/or aspects of otherimplementations as may be desired. Furthermore, to the extent that theterms “includes”, “having”, “has”, “with”, and/or variants thereof areused herein; such terms are intended to be inclusive in meaning—like“comprising.” Also, “exemplary” is merely meant to mean an example,rather than the best. It is also to be appreciated that features, layersand/or elements depicted herein are illustrated with particulardimensions and/or orientations relative to one another for purposes ofsimplicity and ease of understanding, and that the actual dimensionsand/or orientations may differ substantially from that illustratedherein

Therefore, the present disclosure relates to a plasma processing systemcomprising a magnetron configured to provide an adjustable, symmetricmagnetic track through a combination of vibrational and rotationalmotion.

In some embodiments, the present disclosure relates to a physical vapordeposition system, comprising a processing chamber configured to house aworkpiece. A sputtering target is located within the processing chamber.The physical vapor deposition system further comprises a magnetron. Themagnetron comprises a magnetic element positioned on a backside of thesputtering target and configured to generate a magnetic field thatoperates upon ions within the processing chamber. The magnetron furthercomprises a first ambulatory element configured to move the magneticelement in an angular direction and a second ambulatory elementconfigured to linearly move the magnetic element in a radial directionconcurrent to movement in the angular direction. The concurrent angularand radial motion moves the magnetic element along a symmetric magnetictrack.

In another embodiment, the present disclosure relates to a magnetron fora physical vapor deposition system. The magnetron comprises a magneticelement configured to generate a magnetic field that operates upon ionswithin plasma to increase sputtering of a sputtering target. Arotational shaft is operated by a first motor to rotate the magneticelement about a center of the sputtering target. An elastic element isconnected between the magnetic element and the rotational shaft, whereinthe elastic element is configured to vary a radial distance between therotational shaft and the magnetic element during rotation of themagnetic element. The rotational shaft and the elastic element areoperable to move the magnetic element along a symmetric magnetic trackhaving an adjustable path.

In another embodiment, the present disclosure relates to a method foroperating a magnetron to provide an adjustable symmetric magnetic track.The method comprises operating a power source to provide power to amagnetron comprising a magnetic element to generate one or more magneticfields that extend through a sputtering target. The method furthercomprises operating a first ambulatory element to move the magneticelement in an angular direction and operating a second ambulatoryelement to linearly move the magnetic element in a radial directionconcurrent to movement in the angular direction. Moving the magneticelement in both the angular direction and the radial direction providesfor a symmetric magnetic track.

What is claimed is:
 1. A physical vapor deposition system, comprising: aprocessing chamber configured to house a workpiece; a sputtering targetlocated within the processing chamber; a magnetic element positioned ona backside of the sputtering target and configured to generate amagnetic field that operates upon ions within the processing chamber; afirst ambulatory element configured to rotate around a pivot point tomove the magnetic element in an angular direction around an axis ofrotation; a second ambulatory element configured to linearly oscillatethe magnetic element in a radial direction concurrent to movement in theangular direction; and a secondary outside magnet laterally positionedaround a perimeter of the sputtering target at a location verticallyoffset from the sputtering target, and having a bottom surface thatfaces the backside of the sputtering target, wherein the secondaryoutside magnetic element is configured to generate a secondary magneticfield that acts upon the magnetic element with a repulsive force.
 2. Thephysical vapor deposition system of claim 1, wherein the firstambulatory element comprises a rotational shaft configured to rotate themagnetic element about a center of the sputtering target.
 3. Thephysical vapor deposition system of claim 2, wherein the secondambulatory element comprises an elastic element, having a variablelength, which is connected between the magnetic element and therotational shaft along a radial line extending from the rotational shaftto a perimeter of the sputtering target.
 4. The physical vapordeposition system of claim 1, wherein the secondary outside magnetcomprises one or more electromagnetic coils, having axes perpendicularto the axis of rotation, which extend through centers of the one or moreelectromagnetic coils, and wherein the secondary outside magnet isconfigured to dynamically adjust a strength of the secondary magneticfield.
 5. A magnetron for a physical vapor deposition system,comprising: a magnetic element configured to generate a magnetic fieldthat operates upon ions within plasma to increase sputtering of asputtering target; a rotational shaft extending through an axis ofrotation, which is operated by a first motor configured to rotate themagnetic element about a center of the sputtering target; an elasticelement connected between the magnetic element and the rotational shaftand configured to continually vary a radial distance between therotational shaft and the magnetic element during rotation of themagnetic element; and a secondary outside magnet laterally positionedaround a perimeter of the sputtering target, and having a bottom surfacethat faces the sputtering target and that vertically overlies thesputtering target, wherein the secondary outside magnet is configured togenerate a secondary magnetic field that acts upon the magnetic elementwith a repulsive force that pushes the magnetic element in a radiallyinward direction that opposes a centrifugal force, generated by rotationof the magnetic element to provide a radially vibrational motion to themagnetic element.
 6. The magnetron of claim 5, wherein the magneticelement comprises a plurality of permanent magnets.
 7. The magnetron ofclaim 5, wherein the secondary outside magnet comprises one or moreelectromagnets configured to dynamically adjust a strength of thesecondary magnetic field to adjust variable length of the elasticelement.
 8. The magnetron of claim 5, wherein the elastic elementcomprises: a cylinder comprising a moveable piston connected to a springon one side and the magnetic element on an opposite side; and apneumatic valve is configured to control a flow of air into and out ofthe cylinder, wherein a distance of the magnetic element from the centerof the sputtering target is controlled by varying air pressure withinthe cylinder to change a location of the piston.
 9. The magnetron ofclaim 5, wherein the elastic element comprises: a first motor connectedto a rotational shaft aligned along an axis of rotation that extendsthrough the center of a sputtering target; a gear box connected to therotational shaft and located at a position that is laterally offset fromthe axis of rotation, wherein the gear box comprises a second motor incommunication with a screw shaft having a first end connected to themagnetic element and a second end connected to a counter weight; whereinthe gear box is configured to turn the screw shaft based upon operationof the second motor, thereby concurrently moving the magnetic elementand counter weight in a same direction.
 10. The magnetron of claim 5,wherein the elastic element comprises: a first motor connected to arotational shaft aligned along an axis of rotation that extends throughthe center of a sputtering target; a second motor connected to therotational shaft and located at a position that is laterally offset fromthe axis of rotation, wherein the second motor is configured to drive aworm wheel, having teeth with edges that are straight and alignedparallel to an axis of rotation; and a worm gear, having a first endconnected to the magnetic element and a second opposite end connected toa counter weight, meshed with the worm wheel; wherein the worm wheelconcurrently moves the magnetic element and counter weight in a samedirection.
 11. The physical vapor deposition system of claim 1, whereinthe magnetic element is configured to move along a magnetic track at anangular velocity solely defined by the first ambulatory element.
 12. Themagnetron of claim 5, wherein the magnetron is configured to move alonga magnetic track at an angular velocity solely defined by the rotationalshaft.
 13. The physical vapor deposition system of claim 1, wherein thesecond ambulatory element comprises: a cylinder comprising a moveablepiston connected to a spring on one side and the magnetic element on anopposite side; and a pneumatic valve is configured to control a flow ofair into and out of the cylinder, wherein a distance of the magneticelement from a center of the sputtering target is controlled by varyingair pressure within the cylinder to change a location of the piston. 14.A magnetron for a physical vapor deposition system, comprising: a firstambulatory element configured to rotate a magnetic element located alonga backside of a sputtering target in an angular direction around an axisof rotation extending normal to a center of the sputtering target; asecond ambulatory element configured to linearly oscillate the magneticelement in a radial direction concurrent to movement in the angulardirection; and a secondary outside magnetic element comprising aplurality of electromagnetic coils laterally positioned around aperimeter of the sputtering target and vertically separated from a planeextending along a backside of the sputtering target by a space, whereinthe plurality of electromagnetic coils have axes that are perpendicularto the axis of rotation and which extend through centers of theplurality of electromagnetic coils, wherein the plurality ofelectromagnetic coils are configured to generate a secondary magneticfield that operates upon the magnetic element with a repulsive forcethat pushes the magnetic element in a radially inward direction towardsthe center of the sputtering target.
 15. The magnetron of claim 14,wherein the magnetic element comprises a plurality of permanent magnetsoriented to have opposite polarities positioned adjacent to one another.16. The magnetron of claim 14, further comprising: a power systemconnected to the one or more electromagnets and configured to control adirection of current through the plurality of electromagnets to changean orientation of the secondary magnetic field.
 17. The physical vapordeposition system of claim 1, wherein the magnetic element comprises afirst plurality of permanent magnets; wherein the secondary outsidemagnet comprises a second plurality of permanent magnets; and wherein aradially outermost one of the first plurality of permanent magnets andan adjacent radially innermost one of the second plurality of permanentmagnets have magnetic poles that are oriented in a same direction. 18.The physical vapor deposition system of claim 1, further comprising: agrounded chamber shielding laterally disposed between the magneticelement and the secondary outside magnet.
 19. The physical vapordeposition system of claim 1, wherein the magnetic element comprisesconcentric ring shaped magnets having an inner ring-shaped magnet and anouter ring-shaped magnet have a same magnetic polarity.